Nonoverfill device



Dec. 2, 1941. H. HILL NONOVERFILL DEVICE- Filed May 17, 1939 ULlUiH} ATTORNEY/4.-

Patented Dec. 2:, 1941 UNITED STATES PATENT OFFICE NONOVEEFILL Robert 11. nm Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application May 17, 1939, Serial No. 214,151

5 Claims. (01. 136-178) for connecting the space exterior to the skirt and in which air may be trapped in the space within the confines of the skirt. The by-pass is.

controlled by a valve which is automatically closed when the filler hole plug is removed from the cover, and is opened when the plug'ls screwed in place so that the venting of the airtrapping space may take place through thebypass, through the space within the skirt and out through a hole provided by the plug. In i order that the valve will close automatically when the plug is removed, it is necessary to provide means which will urge the valve against its seat and which will yield whenthe valve is pushed away from its seat by screwing the filler hole plug in position. a

It is an object of the present invention to provide a resilient valve closing means-which will not be corroded by the electrolyte of the battery.

According to the present.invention,., I have accomplished this object by a stack of plates or annular discs of acid resisting material such as Bakelite which are'so shaped as to provide, in eifect, a yieldable pad or spring.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanvin'g drawing .wherein a preferred embodiment of the present invention is clearly shown. In the drawing: I

Fig. 1 is a sectional View of a battery cell cover showing the vent valve held in closed position by the resilient stack of Bakelite discs embodying the present invention, the filler plug orxcap being removed as shown at Fig. 1A.

Fig. is a view drawn to larger scale than Fig. 1 showing the filler plug screwed into position and the vent valve opened.

Figs. 3 and 4 which are drawn to the same scale as Fig. 1 show respectively top and bottom views of the stack of Bakelite discs.

Fig. 5 is a fragmentary sectional view on' line 5-5 of Fig.1. g

1A, to permit the pouring of liquid into Referring to Fig. 1, the battery cell cover 20 includes a top wall 2| and side walls :22 having flanges 23 adapted to be supported on ledges pro-.- vided bythe side walls of the battery cell, not shown. It will be understood that the cell construction is such that the top wall of the cover will be substantially flush with the top edges of the battery cell. From the top wall 2| of the cover, a skirt 24 extends downwardly to substantially the desired level of the electrolyte in the battery cell. The skirt is annular and ,is substantially concentric with a threaded filler opening 25'which is adapted to receive a 'filler plug or cap 26 carrying a baflle plate 21, notched at 28, and provided with a' vent 29.

The cover 20 is provided with a by-pass 30 connecting the space exterior to the skirt 24 with the space within the skirt 24. This by-pass' is controlled by a valve 3| mad of hard rubber or other acid resisting material. When the cap 25 is removed as shown at Fig. 1A, the valve '3| is urged upwardly on its "seat 32 by a stack of resilient discs 40 of acid resisting material'such as Bakelite. Seat 32 is one of three bosses 32, 33 and 34, against which th valve 3| is pressed by the stack 40. This stack 40 is confined between-the valve 3| anda hard rubber c -washer 35 which is suificientlyresilient to be compressed and pushed within the skirt 24 and then allowed to snap into a groove 35 provided by the skirt.

When the cap is screwed into position to close the filler opening 25, as shown in Fig. 2, the lower edge of the cap engages an interrupted boss 31 (separated by notches 38) provided by the valve 3|. The resilient stack yields to permit the screwing of the plug into completely closed position and the movement of the valve 3| downwardly from its seat- 32 thus opening the by-pass 30 in order to provide for the venting of the space, above the electrolyte level and exterior to the skirt 24. The venting is provided with the space within the skirt 24 which is open to the outside airth'rough' the notches 38 between the boss segments 31 of the valve 3|,

through "the notches 28 of the battle 2! of the cap 26, as shown in Fig. .1A and .through the vent hole 29. 4 I 7 When the cap 26 isvremoved as she in Fig. the cell through the filler hole 25 in cover 2|], the vent valve 3| is caused to move upwardly dueto'the action of the resilient stack of plates or discs 40, thereby closing the by-pass 30 so that air will be trapped in, the space between the exterionof additional liquid will fill the interior of the skirt 24 without causing appreciable rise of electrolyte in the region exterior to the skirt. The sudden rise of liquid within the skirt indicates that the electrolyte has been brought up to the desired level and that further addition of liquid would result in the liquid overflowing the cover; however, the battery cell will not be overfilled. When the cap 26 is replaced upon the cover, as shown in Fig. 2, the by-pass 30 is opened so as to relieve'the pressure of the air trapped in the space exterior to the skirt whereupon the liquid remaining in the skirt recedes as the electrolyte seeks a common level. As the liquid within the skirt recedes, the level of the electrolyte outside of the skirt is raised by a trifling amount, since the volume or the space within the skirt is but a small percentage of the total volume of the space above the electrolyte and within the confines of the battery cell and cover. In this connection, it will be understood that the cover is oblong in contour and that the sectional view shown in Figs. 1 and 2 are taken across the shorter dimension of the cover.

The stack of resilient plates 40 comprises similar annular discs of Bakelite or other acid resisting material, each provided on its under surface as viewed in Figs. 1 and 2, with diametrically opposite buttons or bosses 4| and 42, the boss 42 being integral also with a lug 43 projectin radially from the outer periphery of the disc. The skirt 24 is provided on its interior with two longitudinally extending grooves 44 and 45, located 90 apart. Groove 44 receives lugs- 43 of alternate discs, and groove 45 receives the lugs 43 of the remaining discs. Thus the discs are so located with respect to each other in staggered relation that each disc will press through its bosses 4i and 42 upon those portions of a contiguous disc which are remote from those portions of that contiguous disc which carry bosses 4| and 42; Therefore, the discs bend in the manner shown in Figs. 1 and 2. By using several discs, it is possible to obtain a substantial amount of deflection without straining any one of the discs beyond its elastic limit, or causing it to break.

While Bakelite is a preferred material for th discs 40, other substances such as glass or hard rubber could be used.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of l the claims which follow. I

What is claimed is as follows:

1. A cell cover construction for storage battery containers comprising a cover having a filler opening and a skirt providing a space communicating with the filler opening, said skirt extending from the top wall of the cover to such a distance that, when the cover is assembled with the battery container, the lower edge of the skirt will be at the proper level ofthe electrolyte within the container, said cover providing a by-pass passage connecting the space exterior to the skirt and under the cover above the electrolyte with the space within the skirt and filler opening, a valve comprising an apertured plate of hard acid resisting material located in the space for engaging the valve to move it from its seat when the plug is assembled with the cover, a resilient stack of flexible apertured discs of hard acid-resisting material supported by the skirt for urging the valve toward its seat, means for spacing the discs from each other at opposite peripheral portions, and means for maintaining the spacing means. in staggered relation so that a disc applies pressure to the next adjacent disc at portions thereof which are remote from portions at which said second-mentioned disc applies pressure to that disc which is next adjacent to the second-mentioned disc.

2. A cell cover construction for storage battery containers comprising a cover having a filler opening and a skirt providing a space communicating with the filler opening, said skirt extending from the top wall of the cover to such a distance that, when the cover is assembled with the battery container, the lower edge of the skirt will be at the proper level of the electrolyte within the container, said cover providing a by-pass passage connecting the space exterior to the skirt and under the cover above the electrolyte with the space within the skirt and filler opening, a ring valve of hard acid resisting material located in the space within the skirt and engageable with a seat provided by the cover in order to close the by-pass, a vented plug for closing the filler opening and for engaging thevalve to move it from its seat when the plug is assembled with the cover, a resilient stack of flexible apertured plates of hard acid-resisting material supported by the skirt for urging the valve toward its seat, each plate being provided with bosses on opposite peripheral portions of the plate, and means provided by the plates and skirt for maintaining the bosses of the plates in staggered relation whereby the bosses of a plate bear against portions of a contiguous plate which are remote from those portions of the contiguous plate which carry the bosses.

3. A cell cover construction for storage battery containers according to claim 2, in which the plates are of hard acid resisting material and of annular formation, each provided with bosses at diametrically opposite peripheral portions therefore, and each provided with a lug, and in which the interiorwall of the skirt is provided with two longitudinally extending grooves spaced apart, each groove receiving the lugs of alternate plates.

4. In a storage battery, a cell cover structure having a skirt depending thereupon to a predetermined electrolyte level and defining a cell filler opening therewithin and a covered gas space thereabout, a by-pass duct in said cover structure providing communication between said gas space and said filler opening, said duct terminating as a closable port within the filler opening, a vented closure plug disposable in said filler opening, a valve member disposed within said filler opening and normally held from seatedrelation with said duct port when said closure plug is assembled but capable of effecting closure of said duct port when said plug is removed, a stack of resiliently flexible apertured tween, said points of contact between contiguous members of the stack being staggered with respect to the points ofcontact between adjacent members of the stack so as to permit flexure of said members and provide substantial compressibility in the spacedly stacked assembly, and

means for maintaining said stack of members within said skirt and under partial compression against said valve member biasing same toward port-closing position.

5. In .a storage battery, a cell cover structure having a skirt depending therefrom to a predetermined electrolyte level and defining a cell filler opening therewithin and a covered gas space thereabout, a by-pass duct in said cover structure providing communication between said gas space and said filler opening, said duct terminating as a clos able port within the filler opening, a vented closure plug disposable in said filler opening, a valv member disposed within said filler opening and normally held from seated relation with said duct port when said closure plug is assembled but capable of eiiecting closure of said duct port when said plug is removed, a stack of resiliently flexible apertured members of non-compressible acid-resistant material arranged in stacked relation beneath said valve member, each having contact with the next apertured member solely at localized points provide ing substantial zones of spacing therebetween, said points of contact between contiguous membersoi the stack being staggered with respect to the points of contact between adjacent members of th stack so as to permit flexure of said members and provide substantial compressibility in the spacedly stacked assembly, means for assuring assembly and maintenance of said members in the arrangement stated, and means for maintaining said stack of members under partial compression against said valve member to bias .same

toward port-closing position.

I ROBERT H. HILL. 

